Medial open wedge high tibial osteotomy: can delayed or nonunion be predicted?

Infection in osteotomy around the knee: Incidence, management and outcomes in a high-volume case series

PURPOSE

Current evidence around the management of osteotomy-related infection is insufficient to robustly underpin the expert statements formulated by a recent European consensus statement. We present a review of a large case series in a high-volume osteotomy practice to contribute to the understanding of the incidence, management and outcome of infection in this subspecialty area.

METHODS

Analyses of two prospectively collected databases for all osteotomy around the knee and infections related to osteotomy were performed, along with a review of hospital readmission data to capture all osteotomy-related infections. Clinical notes were reviewed to assess patient demographics, incidence of infection, how infection was managed and clinical outcome.

RESULTS

In a series of 822 osteotomies in 755 patients, there were 21 (2.8%) cases of suspected infection. Twelve (1.6%) were contemporaneously deemed 'superficial' and nine confirmed 'deep' infections (1.2%). Deep infections were all successfully managed with wound debridement, with or without plate removal, depending on union and time from initial surgery. One of these infections was noted during a revision procedure, but no revision was carried out as a direct result of infection, no external fixation was required and no infected nonunions were experienced.

CONCLUSION

All of the cases in this series were managed successfully with debridement ± removal of the plate, without the need for revision or external fixation. Any potential signs of infection around an osteotomy, especially in the case of medial high tibial osteotomy, should raise awareness for deep infection and the need for further surgery due to the limited overlying soft tissue cover. This evidence supports the recent European Society of Sports Traumatology, Knee Surgery and Arthroscopy algorithm.

LEVEL OF EVIDENCE

Level IV, case series.

Comparison of short-term clinical outcomes between open-wedge high tibial osteotomy and tibial condylar valgus osteotomy

BACKGROUND

This study aimed to compare radiological features and short-term clinical outcomes between open-wedge high tibial osteotomy (OWHTO) and tibial condylar valgus osteotomy (TCVO), to provide information facilitating decision-making regarding those two procedures.

METHODS

Twenty-seven cases involving 30 knees that had undergone OWHTO (HTO group) and eighteen cases involving 19 knees that had undergone TCVO (TCVO group) for medial compartment knee osteoarthritis (OA) were retrospectively evaluated. Patient characteristics, severity of knee OA, lower limb alignment, joint congruity and instability were measured from standing full-length leg and knee radiographs obtained before and 1 year after surgery. Range of motion in the knee joint was measured and Knee Injury and Osteoarthritis Outcome Score (KOOS) was obtained to evaluate clinical results preoperatively and 1 year postoperatively.

RESULTS

Mean age was significantly higher in the TCVO group than in the HTO group. Radiological features in the TCVO group included greater frequencies of advanced knee OA, varus lower limb malalignment, higher joint line convergence angle, and varus-valgus joint instability compared to the HTO group before surgery. However, alignment of the lower limb and joint instability improved to comparable levels after surgery in both groups. Maximum flexion angles were significantly lower in the TCVO group than in the HTO group both pre- and postoperatively. Mean values in all KOOS subscales recovered similarly after surgery in both groups, although postoperative scores on three subscales (Symptom, Pain, and ADL) were lower in the TCVO group (Symptom: HTO, 79.0; TCVO, 67.5; Pain: HTO, 80.5; TCVO, 71.1; ADL: HTO, 86.9; TCVO, 78.0).

CONCLUSIONS

Both osteotomy procedures improved short-term clinical outcomes postoperatively. TCVO appears preferable in cases of advanced knee OA with incongruity and high varus-valgus joint instability. An appropriate choice of osteotomy procedure is important to obtain favorable clinical outcomes.

Incidence of Complications and Revision Surgery After High Tibial Osteotomy: A Systematic Review

BACKGROUND

High tibial osteotomy (HTO) is a well-recognized procedure for its effectiveness in treating symptomatic early knee arthritis and malalignment. Although there are numerous systematic reviews evaluating the management and outcomes after HTO, there are few investigations on complications of this procedure.

PURPOSE

To systematically review the literature to determine the incidence of intraoperative and postoperative complications associated with medial opening wedge and lateral closing wedge HTOs.

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

The Cochrane Database of Systematic Reviews, PubMed, Embase, and MEDLINE databases were queried for studies reporting complications associated with HTO with or without concomitant procedures. Data including patient characteristics, procedure type, concomitant procedures, follow-up time, and postoperative imaging were extracted. Rates of intra- and postoperative complications, reoperations, and conversion to arthroplasty were recorded.

RESULTS

A total of 71 studies were included for analysis, comprising 7836 patients. The overall intraoperative complication rate during HTO was 5.5% (range, 0%-29.3%), and the overall postoperative complication rate was 6.9% (range, 0%-26.6%). The most common intraoperative complication was lateral hinge fracture (incidence, 9.1%; range, 0%-30.4%) in medially based HTOs and peroneal nerve injury in laterally based HTOs (incidence, 3.2%; range, 0%-8.7%). The overall incidence of neurovascular injury after medially or laterally based HTOs was 1.1% (range, 0%-18.9%). The most common postoperative complication was superficial infection (incidence, 2.2%; range, 0%-13%). Of the included studies, 62 included postoperative radiographic analysis, and among those, the incidence of nonunion was 1.9% (range, 0%-15.5%), loss of correction was 1.2% (range, 0%-34.3%), and implant failure was 1.0% (range, 0%-10.2%). Among studies reporting revision surgeries, the overall reoperation rate was 15.5% (range, 0%-70.7%), with the most common type of reoperation being hardware removal (incidence, 10.0%; range, 0%-60%).

CONCLUSION

Intraoperatively, medially based HTOs are associated with a 1 in 11 risk of lateral hinge fracture and laterally based HTOs with a 1 in 30 risk of peroneal nerve injury. Postoperative complication rates in the range of 10% to 15% can be expected, including infection (2.9%), loss of correction (1.2%), and nonunion (1.9%). Patients should also be counseled that the reoperation rate is approximately 15%, with hardware removal being the most common procedure.

Bone Healing and Clinical Outcome Following Medial Opening-wedge High Tibial Osteotomy Using Wedge-Shaped Cancellous Allograft

OBJECTIVE

Medial opening-wedge high tibial osteotomy (MOWHTO) is considered to be an effective treatment for symptomatic knee osteoarthritis (KOA) of isolated the medial compartment with varus alignment of the lower extremity. However, the choice of material to fill the void remains controversial. This study aims to evaluate the bone union of the osteotomy gap using a novel wedge-shaped cancellous allograft after MOWHTO and its effect on clinical outcomes.

METHODS

All patients who underwent MOWHTO using a novel wedge-shaped cancellous allograft combined with TomoFix locking compression plate (LCP) fixation between January 2016 and July 2020 were enrolled. The radiographic parameters including hip-knee-ankle angle (HKAA), medial proximal tibial angle (MPTA), femorotibial angle (FTA) and posterior tibial slope angle (PTSA) were measured between pre-operative and post-operative radiographs. Knee Society score (KSS) and range of motion (ROM) were assessed preoperatively and at last follow-up. Patients included in this study were divided into two groups according to the correction angle: small correction group (< 10°; SC group) and large correction group (≥ 10°; LC group). The modified Radiographic Union score for tibial fractures (mRUST) was used to assess the difference in bone healing between the two groups at 1, 3, 6, and 12 months postoperatively and at the final follow-up. A paired student's t test was conducted for comparison of differences of the relevant data pre-operatively and post-operatively.

RESULTS

A total of 82 patients (88 knees) were included in this study. The HKAA, MPTA, FTA and PTSA increased from -6.4° ± 3.0°, 85.1° ± 2.6°, 180.1° ± 3.2° and 7.7° ± 4.4° preoperatively to 1.2° ± 4.3° (p < 0.001), 94.4° ± 3.3° (p < 0.001), 171.0° ± 2.8° and 11.8° ± 5.8° (p < 0.001) immediately postoperatively, respectively. However, no significant statistic difference was found in above-mentioned parameters at last follow-up compared to immediate postoperative data (p > 0.05). All patients in this study achieved good bone healing at the final follow-up and no significant differences in mRUST scores were seen between the SC group and LC group. The KSS-Knee score and KSS-Function score improved significantly from 55.4 ± 3.7 and 63.3 ± 4.6 preoperatively to 86.4 ± 2.8 (p < 0.001) and 89.6 ± 2.9 (p < 0.001) at last follow-up, respectively. Nevertheless, there was no significant difference in ROM between pre-operation and last follow-up (p > 0.05).

CONCLUSION

For MOWHTO, the wedge-shaped cancellous allograft was a reliable choice for providing good bone healing and clinical outcomes.

Better clinical outcomes and faster weight bearing after medial opening-wedge high tibial osteotomy using allogeneic than synthetic graft: A secondary analysis of a Francophone Arthroscopy Society Symposium

INTRODUCTION

Although an autogenous graft has the highest rate of bone union to fill the void created in medial opening wedge high tibial osteotomy (MOWHTO), it also has some disadvantages, such as prolonged surgical time, donor site pain and morbidity. Two possible candidates for ideal grafts to replace autogenous grafts are allogeneic and synthetic graft, which are free from donor site pain and morbidity. However, previous reports comparing the clinical results of allogeneic to synthetic graft have been limited and controversial. The purpose of this study is to compare radiological findings and clinical outcomes of using synthetic versus allogenic graft to fill the void created in MOWHTO.

HYPOTHESIS

The present clinical study hypothesized that allogenic graft to fill the void would allow the higher rate of bone union and better clinical outcomes.

MATERIAL AND METHODS

This study compared the clinical and radiological outcomes of 95 patients who received MOWHTO to fill the void with either synthetic or allogenic graft (44 in Syn group, 51 in Allo group). Preoperatively and postoperatively, all patients were clinically evaluated; Return to work, Tegner activity score, and the Western Ontario and Macmaster University scores were reported. Radiographically, osteoarthritis grade and pre- and postoperative parameters were reported, including Hip-knee-ankle angle, mechanical lateral distal femoral angle, medial proximal tibial angle, joint line convergence angle, proximal posterior tibial angle, and limb length discrepancy. Perioperative details and complications were also reported.

RESULTS

Mean follow-up (months) were 24.0±1.3 in Syn group and 26.8±1.2 in Allo group (p=0.13). The postoperative improvement of pain and global WOMAC scores in Allo group were significantly better than in Syn group (ΔPain of WOMAC: Syn group 27.8±4.4, Allo group 49.3±3.8, p value <0.001*) (ΔGlobal score of WOMAC: Syn group 16.7±3.2, Allo group 37.4±4.9, p value=0.002*). The risk of hinge fracture in Syn group was significantly higher than in Allo group (Hinge fracture by Takeuchi grade (0/1/2/3): Syn group 37/3/3/1, Allo group 43/8/0/0, p value=0.04*). The timing of full weight bearing in Allo group was significantly earlier than in Syn group (Weight Bearing (1=FWB, 2=PWB 3wk, 3=PWB 6wk): Syn group 2.7±0.1, Allo group 2.3±0.1, p value=0.01*).

DISCUSSION

The use of allogenic graft to fill the void in MOWHTO does not show superiority in bone union compared to synthetic graft, however it improves pain, function, decreases the risk of hinge fracture and allows faster weight bearing than synthetic graft.

LEVEL OF PROOF

III; Case-control study.

The effect of smoking on union rates following corrective osteotomies around the knee: A systematic review and meta-analysis

BACKGROUND

Distal femur osteotomies (DFO) and high tibial osteotomies (HTO), are well-established treatment options for joint preservation in active patients with uni-compartmental osteoarthritis. Optimal outcomes are contingent on adequate preoperative evaluation of patient-specific factors. This systematic review and meta-analysis aims to explore the difference in union rates between smokers and non-smokers following corrective osteotomies around the knee.

METHODS

A systematic search of the MEDLINE and EMBASE databases was performed in accordance with the PRISMA guidelines to identify studies reporting smoking status in adults who developed delayed and/or non-union following HTO or DFO. Studies were pooled using a random effect model [Review Manager (RevMan) software, V.5.4] and heterogeneity was estimated using I2.

RESULTS

Data for meta-analysis was available for 1,406 osteotomies from 10 studies, performed in patients with mean age ranging from 38-54 years, and 65% were male. The union rate among non-smokers was 97.3% (1100/1131) compared with 89.5% (246/275) among smokers; OR 4.59 [95% CI 1.99 to 10.62], p-value < 0.001. Subgroup analysis revealed that the risk of non-union in smokers after opening wedge osteotomy was almost double (OR 4.8) that of closing wedge osteotomies (OR 2.9).

CONCLUSION

Smoking increases the risk of non-union during elective knee osteotomy surgery. Our findings also suggest that smokers have a better chance of achieving union with closing wedge osteotomy compared to open wedge osteotomy.

Effect of Patient Age on Clinical and Radiological Outcomes After Medial Open-Wedge High Tibial Osteotomy: A Comparative Study With 344 Knees

Background

There exists some controversy regarding whether patient age is a predictive factor for outcomes after high tibial osteotomy (HTO).

Purpose/Hypothesis

The purpose of this study was to evaluate whether patient age affects clinical and radiological outcomes after medial open-wedge HTO (OWHTO) in a large population with a wider age range than previous studies. It was hypothesized that there would be no differences in outcomes when compared across age-groups.

Study Design

Cohort study; Level of evidence, 3.

Methods

A retrospective comparative study was conducted using 344 patients (303 knees) who underwent OWHTO from 2009 to 2018. These patients were divided into 3 groups based on age at the time of surgery: ≥55 years (group Y: 76 knees in 57 patients), 56 to 64 years (group M: 129 knees in 120 patients), and ≤65 years (group O: 139 knees in 126 patients). Clinical and radiological evaluations were performed immediately before surgery and at the final follow-up period, at a mean of 5.1 years (range, 3-11 years). Comparisons among the 3 groups were conducted with 1-way analysis of variance for continuous variables. When a significant result was obtained, a post hoc test with Bonferroni correction was conducted for multiple comparisons.

Results

In clinical evaluations, there were no significant differences among the 3 groups either preoperatively or postoperatively concerning the Japanese Orthopaedic Association score, the Lysholm score, or the Knee injury and Osteoarthritis Outcome Score (KOOS), with the exception of the preoperative KOOS Symptoms subscale, which was significantly higher in group Y versus group O (48.9 ± 18.7 vs 58.7 ± 15.4, respectively; P = .011). The Tegner activity score was significantly different among the groups, both preoperatively and postoperatively (P < .001 for both). There was no significant difference in the occurrence of complications or the survival rate at final follow-up among the 3 groups.

Conclusion

The study findings suggest that patient age does not affect clinical and radiological outcomes after OWHTO.

Lateral hinge fracture in medial opening wedge high tibial osteotomy: a narrative review

Lateral hinge fractures (LHF) are one of the most common complications of medial opening wedge high tibial osteotomy (MOWHTO), and are the leading cause of construct instability displacement, non-union, and varus recurrence after this procedure. To date, Takeuchi's classification is the most popular classification to describe this complication, and it can help surgeons to make intra and postoperative decisions. Opening medial gap width is the most recognized factor related to LHF occurrence. Recognizing the implications of LHF in patients' clinical and radiographic results has led many authors to propose surgical tips and the use of osteosynthesis materials such as K-wires and screws for its prevention, which should be considered when identifying risk factors for LHF during preoperative planning. The evidence for determining the optimal management of LHF is scarce and mostly supported by experts' opinions and recommendations; therefore, studies are still needed to identify the most appropriate behavior when dealing with such a complication.

[Treatment of unicompartmental osteoarthritis of the knee]

Osteoarthritis of the knee is one of the most important degenerative joint diseases in the clinical routine. The treatment of knee osteoarthritis is not only based on the stage, symptoms and duration of the joint disease, but also depends on the existing arthrosis pattern. In the case of unicompartmental arthrosis, damage typical for osteoarthritis is limited to just one joint compartment. Both the conservative and the surgical treatment of unicompartmental osteoarthritis of the knee have to respect the individual characteristics of the respective forms of osteoarthritis. In the context of this manuscript, the genesis, the diagnostics and the guideline-based stage-adapted conservative and operative treatment of unicompartmental osteoarthritis of the knee are addressed.

Clinical Outcome after Medial Open-Wedge High Tibial Osteotomy: Comparison of Two Angular Stable Locking Plates—TomoFix™ versus LOQTEQ® HTO Plate

This study evaluated bony healing and clinical results after medial open-wedge HTO to compare the outcome of the LOQTEQ® HTO plate and the TomoFix™ internal plate fixator. A prospective, non-randomised, comparative study was undertaken. The same surgical technique for the medial open-wedge HTO was used in two treatment groups. In Group 1, the TomoFix™ implant was used for osteosynthesis, and, in Group 2, the LOQTEQ® HTO plate was used. All patients were examined before surgery (T0) and then at 12 months (T1) and at 24 months (T2) postoperatively. The primary outcome measure was the KOOS pain subscore. The secondary outcome criteria were other KOOS subscales, the Tegner score, radiological healing (RUST), and incision length. The KOOS pain subscale and the other KOOS subscores increased significantly in both groups from T0 to T1 and T2 without a significant group difference at each timepoint. The activity measured with the Tegner scale increased significantly from T0 to T2 without a significant group difference. No radiological signs of implant failure were observed in any case at the one-year X-ray, and no patient fulfilled the criteria for non-union. There was no significant difference in the frequency of adverse effects between the two treatment groups. The length of the incision was significantly shorter in the LOQTEQ® HTO group than in the TomoFix™ group. The results of this study show that patient-related outcome scores (KOOS, Tegner) increased after medial open-wedge HTO. There was no difference in clinical outcome or radiological healing between the treatment groups. Both plates are suitable for the osteosynthesis of open-wedge HTO.

Intra-Observational and Inter-Observer Agreement of The Radiographic Humerus Union Measurement (RHUM) in Patients Treated with Dynamic Compression Plate for Humeral Shaft Nonunion

BACKGROUND

It is important for orthopedic surgeons to follow the union of the fracture after surgery. This becomes even more important after nonunion surgery. The radiological union scale is popular in the follow-up of unions. However, the intraobserver and interobserver agreement of this scale in humeral nonunion surgery is still not found in the literature.

OBJECTIVE

This study aimed to reveal the intra/interobserver agreement of the Radiographic Union scale (RHUM) for the humerus as well as the relationship between this agreement, plate placement characteristics, and the number of plates in cases where plates were used for surgical treatment of humeral diaphysis nonunion.

MATERIALS AND METHODS

Twenty patients who received surgical treatment for aseptic humeral nonunion at our hospital between 2010-2019 were studied retrospectively. According to RHUM, two observers scored the patients' anteroposterior and lateral radiographs in the postoperative 12th week. The data obtained were statistically analyzed.

RESULTS

The mean age was 52.05±15.88 years. While a single plate was used in 14 cases, a double plate was used in 6 cases. Interobserver agreement was fair-moderate. The interobserver agreement values of the single plate group were significantly higher than those of the double plate group (p<0.05). Interobserver agreement in cases with a lateral plate was significantly higher than in the group where the lateral + posterior plate was applied (p:0.01).

CONCLUSION

In humeral diaphyseal fracture nonunion cases, the number and location of the plate following surgery negatively impact the evaluation of RHUM scores. Given the importance of the union's follow-up and the decision to proceed with additional treatment in these cases, it may be necessary to develop a new method for determining and monitoring the union if a plate was used in the surgical treatment of humeral nonunion.

Complications after high tibial osteotomy and distal femoral osteotomy are associated with increasing medical comorbidities and tobacco use

PURPOSE

The purpose of this study was to assess complications, reoperations, and their risk factors at 90 days and 2 years after high tibial osteotomy (HTO) and distal femoral osteotomy (DFO) in a national cohort.

METHODS

The PearlDiver Mariner Dataset was queried using International Classification of Diseases (ICD) and Current Procedural Terminology (CPT) codes for HTO and DFO, complications, and subsequent surgery. Minimum follow-up was 2 years and complications were assessed at 90 days and 2 years. Hospital readmission in the first 90 days was also assessed. Univariate and multiple logistic regression were utilized to identify risk factors for complications and re-operation.

RESULTS

The 90-day and 2-year complication rates after HTO (n = 1780) were 11.6% and 31.7%, compared to 21.5% (p < 0.0001) and 41.5% (p = 0.0001) after DFO (n = 446). Infection was the most frequent early (90-day) complication for both HTO and DFO cohorts, while hardware problems were most common at 2 years. Increasing Elixhauser Comorbidity Index (ECI) was associated with increased odds of infection, readmission, and hardware-associated complications in both cohorts. Gender and tobacco use were also associated with various complications after HTO. At 2 years, 23.7% of HTO patients and 26.2% of DFO patients had undergone subsequent surgery. Hardware removal occurred in 16.4% of HTO and 18.4% of DFO patients (n.s.), while 4.5% of HTO and 5.2% of DFO patients underwent total knee arthroplasty (TKA) within 2 years (n.s.).

CONCLUSION

HTO and DFO have substantial complication rates in the short and mid term, with a higher rate of overall complications observed after DFO as compared to the HTO cohort. After both procedures, roughly one quarter of patients will undergo subsequent surgery within 2 years. Patients with tobacco use and numerous medical co-morbidities may not be optimal candidates due to increased complication rates. Elixhauser Comorbidity Index (ECI) may be an useful tool for risk assessment prior to surgery.

LEVEL OF EVIDENCE

Retrospective cohort study, III.

A predictive score of high tibial osteotomy survivorship to help in surgical decision-making: the SKOOP score

INTRODUCTION

The high tibial osteotomy (HTO) survival rate is strongly correlated with surgical indications and predictive factors. This study aims to assess HTO survival in the long term, to determine the main predictive factors of this survival, to propose a predictive score for HTO based on those factors.

METHODS

This multicentric study included 481 HTO between 2004 and 2015. The inclusion criteria were all primary HTO in patients 70 years old and younger, without previous anterior cruciate ligament injury, and without the limitation of body mass index (BMI). The assessed data were preoperative clinical and radiological parameters, the surgical technique, the complications, the HKA (hip knee ankle angle) correction postoperatively, and the surgical revision at the last follow-up.

RESULTS

The mean follow-up was 7.8 ± 2.9 years. The HTO survival was 93.1% at 5 years and 74.1% at 10 years. Age < 55, female sex, BMI < 25 kg/m² and incomplete narrowing were preoperative factors that positively impacted HTO survival. A postoperative HKA angle greater than 180° was a positive factor for HTO survival. The SKOOP (Sfa Knee OsteOtomy Predictive) score, including age (threshold value of 55 years), BMI (threshold values of 25 and 35 kg/m²), and the presence or absence of complete joint line narrowing, have been described. If the scale was greater than 3, the survival probability was significantly lower (p < 0.001) than if the scale was less than 3.

CONCLUSION

A predictive score including age, BMI, and the presence or absence of joint line narrowing can be a helpful in making decisions about HTO, particularly in borderline cases.

LEVEL OF EVIDENCE

Retrospective cohort study.

Smoking cessation intervention prior to orthopedic surgery: A study protocol to determine patient outcomes and feasibility

The aim of the study is to analyze the effect of smoking and smoking cessation on the incidence of complications among orthopedic and hand surgery patients, and to determine the feasibility of smoking cessation intervention, as well as factors predicting success in smoking cessation. Orthopedic and hand surgery patients will be invited to participate in the study, which will recruit 550 participants (at least 20% daily smokers). A participant will be defined as a daily smoker if he/she reports daily smoking and/or laboratory tests show active smoking. Data will be collected using a self-reported questionnaire and from medical records. Smokers will receive information about the benefits of smoking cessation and will be encouraged to quit. Medication or nicotine replacement therapy will be prescribed. Laboratory tests will be taken two weeks before and two weeks after surgery. Follow-up phone calls will be made at 3, 6, and 12 months after surgery. The primary outcome is any complication, defined as a prolonged stay in hospital or any additional visit to or measure taken by a health service during the 12 months after surgery. Data on complications are mainly obtained from personal health records and from the information received at the follow-up; the rest of the data will be collected from the register of healthcare-associated infections. Secondary outcomes are the number and types of complications. The sample (n=550) was calculated to observe a 10% difference in complications between smokers and non-smokers (5% alpha level and 80% power), considering a 10% drop-out rate. Logistic regression and log-linear models will be used for data analyses.

A comparative study of 6-week and 12-week Radiographic Union Scores for HUmeral fractures (RUSHU) as a predictor of humeral shaft non-union

BACKGROUND

Non-union in non-operatively managed humeral shaft fractures are associated with significant morbidity. Hence, developing a robust system that could help with early diagnosis is important. We aimed to evaluate the validity of the Radiographic Union Score for HUmeral fractures (RUSHU) at 6 weeks (RUSHU-6) and test whether a RUSHU at 12 weeks (RUSHU-12) would be a better predictor of non-union.

METHODS

We retrospectively reviewed all non-operatively managed humeral diaphyseal fractures from 2012 to 2018. Statistical analysis was used to determine the cut-off RUSHU-12 and evaluate the effect of RUSHU-6 and RUSHU-12 on non-union prediction.

RESULTS

In sum, 32 patients had radiographs at 6 weeks post-injury, 27 of which also had radiographs at 12 weeks. A RUSHU cut-off of 9 was the best predictor of non-union at 12 weeks. Only RUSHU-12 had a statistically significant influence predicting non-union (P = 0.011) and there was a significant correlation (P = 0.003) between score progression from RUSHU-6 to RUSHU-12 and the development of non-union.

DISCUSSION

A RUSHU-12 of <9 and a low score progression between 6 and 12 weeks suggest superior predictive value in determining the likelihood of non-union. Further validation in the form of a large multicentred study is however required.

Bone healing on serial plain radiographs occurs slowly but adequately after medial opening wedge high tibial osteotomy without bone graft

PURPOSE

The purpose of this study was to prospectively investigate osteotomy gap filling rates on serial plain radiographs, and to evaluate whether alignment correction is maintained after medial opening wedge high tibial osteotomy (MOWHTO) using a locking plate without bone graft.

METHODS

Between March 2014 and June 2017, MOWHTO was performed without bone graft regardless of gap size. Radiographs were taken preoperatively, postoperatively, at 1, 3, 6, 12, 18, and 24 months after surgery. Radiographic examinations included a weight bearing long-standing anteroposterior (AP) view of the whole lower extremity, as well as, the AP, lateral, and both oblique views of the knee. Bone healing was measured on the medial oblique view of the knee. The postoperative alignment correction and its maintenance were assessed using the three radiologic parameters of the weight-bearing line (WBL) ratio, the hip-knee-ankle angle (HKAA), and the medial proximal tibial angle (MPTA) on the weight-bearing long-standing AP view of the lower extremity.

RESULTS

Fifty-two consecutive patients underwent MOWHTO, but three patients failed to follow-up for more than 24 months. A total of 49 patients were assessed in this study. The median opening gap height was 10.0 mm (IQR, 8.0-12.0; range, 7-20). On immediate post-operative radiographs, the mean gap filling was 31.4 ± 3.6%. After 1, 3, 6, 12, 18, and 24 months, the mean gap filling rates increased to 38.7 ± 4.4%, 51.4 ± 6.6%, 66.5 ± 5.1%, 84.8 ± 7.0%, 92.4 ± 5.6%, and 97.8 ± 2.3%, respectively. Statistical differences were observed between all the follow-up evaluations (P < 0.001). Statistical differences in the WBL ratio, HKAA, and MPTA were observed between preoperatively and 1 month after surgery (P < 0.001). The mean PTSA increased significantly from preoperatively to postoperatively (P < 0.001). However, no statistical differences were found between the post-operative follow-up radiographs performed for these four values.

CONCLUSION

MOWHTO using a locking plate without bone graft achieved at least 90% bone healing and had no loss in correction at 2 years postoperatively.

LEVEL OF EVIDENCE

III.

High Tibial Osteotomies for the Treatment of Osteoarthritis of the Knee

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A high tibial osteotomy (HTO) is a joint-preserving procedure that can be used to treat symptomatic unicompartmental cartilage disorders in the presence of limb malalignment.

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Appropriate patient selection and careful preoperative planning are vital for optimizing outcomes.

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Based on past literature, correction of varus malalignment to 3° to 8° of valgus appears to lead to favorable results. Recently, there has been growing awareness that it is important to consider soft-tissue laxity during preoperative planning.

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Although there has been a recent trend toward performing opening-wedge rather than closing-wedge or dome HTOs for unicompartmental osteoarthritis, current data suggest that all 3 are acceptable techniques with varying complication profiles.

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Based on current evidence, an HTO provides pain relief, functional improvement, and a high rate of return to sport, with reported survivorship ranging from 74.7% to 97.6% and 66.0% to 90.4% at 10 and 15 years, respectively.

Long-term follow-up results of medial opening wedge high tibia osteotomy with a pre-countered non-locking steel plate

INTRODUCTION

This retrospective study investigated the long-term follow-up results of medial opening wedge high tibial osteotomy (MOWHTO) with a pre-countered non-locking steel plate implant (Puddu plate = PP) used for medial knee osteoarthrosis (OA) treatment.

MATERIALS AND METHODS

Consecutive 70 MOWHTOs (66 patients) were performed between 01.01.2004 and 31.12.2008 with the mean follow-up time of 11.4 (SD 4.5; range 1.2-16.1) years. The Kaplan-Meier survival analysis was used to evaluate the cumulative survival of the implant in terms of age (< 50 years old and ≥ 50 years old) and gender. Adverse events were studied and Cox regression analysis was used to evaluate risk factors [age, gender, body mass index (BMI), preoperative mechanical axis, severity of OA, use of bone grafting or substitution and undercorrection of mechanical axis from varus to valgus] for revisions.

RESULTS

The estimates for the cumulative survival with no need for TKA after MOWHTO were 86% at 5 years, 67% at 10 years and 58% at 16.1 years (SE 0.6, CI 95% 11.1-13.5). A total of 33/70 (47%) adverse events occurred and 38/70 (54%) knees required some revision surgery during the follow-up. Cox regression did not show any statistically significant risk factors for revision.

CONCLUSIONS

The PP has feasible MOWHTO results with a cumulative survival of 67% at 10 years with no need for conversion to TKA. Many adverse events occurred and revision rate due to any reason was high. Age or gender did not have statistically significant differences in terms of survival.

High Tibial Osteotomy: An Update for Radiologists

High tibial osteotomy (HTO) is a surgical procedure to treat symptomatic unicompartmental osteoarthritis (OA) associated with knee malalignment. There has been a recent resurgence of interest in HTO in patients who prefer joint-preserving surgery, as HTO shifts the knee's mechanical axis from the arthritic compartment to a neutral position, thereby reducing knee pain, slowing progression of OA, and delaying the need for a total knee arthroplasty. The ideal candidates for HTO are young, active, nonobese patients with isolated varus deformity of the knee due to medial compartment OA. Radiography is critical in the preoperative evaluation for HTO and can help expand surgical indications to include a wider variety of patients. Radiography is also routinely obtained in postoperative assessment and is typically the first test to suspect complications. This review describes the radiologic aspects of HTO, including preoperative imaging assessment, as well as normal and abnormal postoperative imaging appearances. Surgical techniques and osteotomy fixation devices are described, with a focus on the medial opening wedge approach. Given the growing interest in HTO, radiologists should become familiar with the basics of the procedure and the role of imaging in preoperative and postoperative evaluation.

Acute Correction and Plate Fixation for the Management of Severe Infantile Blount's Disease: Short-term Results

Purpose

The purpose of this study is to evaluate the short-term results of lateral closing wedge osteotomy with medial hemiplateau elevation for the management of severe infantile Blount's disease.

Materials and methods

In this prospective study, 11 cases of severe Blount's disease (Langenskiold stages five and six) were managed in the period between January 2017 and January 2020. Double osteotomy technique was applied, namely a metaphyseal closing wedge and a medial hemiplateau elevation, through a single midline incision. Fixation was achieved by a medial anatomical locked plate. Patients were evaluated clinically according to a modified version of paediatric outcomes data collection Instrument (PODCI) and radiologically by measuring the angle between the tibial and the femoral shaft, the mechanical axis deviation (MAD) and the angle of the medial tibial plateau (MTP) depression.

Results

The average follow-up period was 2 years. Healing of the osteotomies was achieved in all cases after the index operation within an average of 3 months. Based on our modification of the PODCI score, five cases had an excellent outcome, five were good, and one case ended with a fair outcome. No major complications were encountered in this study.

Conclusion

The management of severe Blount's disease by acute correction using the aforementioned technique has been proven to achieve acceptable clinical and radiological outcomes without significant complications.

Level of evidence

Level IV case series study.

How to cite this article

Nada AA, Hammad ME, Eltanahy AF, et al. Acute Correction and Plate Fixation for the Management of Severe Infantile Blount's Disease: Short-term Results. Strategies Trauma Limb Reconstr 2021;16(2):78–85.

Orientation and end zone of the osteotomy cut for high tibial osteotomy: Influence on the risk of lateral hinge fracture. A finite element analysis

INTRODUCTION

the hinge plays a fundamental role in the support and consolidation of a high tibial osteotomy. The objective of this work was to analyse the influence of the end zone of the osteotomy cut and its orientation in relation to the articular joint line (JL) on the risk of hinge fracture.

HYPOTHESIS

a specific orientation and end zone of the osteotomy cut can be utilised to decrease the risk of hinge fracture.

MATERIAL AND METHOD

a finite element (FE) model was used to reproduce the proximal portion of the tibia and the proximal tibiofibular joint with transverse isotropic elastic bone properties. A 1.27mm thick, complete, anteroposterior saw cut was made with a U-shaped saw blade. Five proximal and lateral tibial zones were used according to Nakamura et al corresponding to the end zones of the osteotomy cut. Three angulations of the cut relative to the JL were defined: 10°, 15°, 20°. The tests consisted of simulating 15 possible situations (3 angulations for each of the 5 end zones) on this model. These simulations made it possible to identify the existence of a local stress concentration (von Mises, in MPa) at the level of the hinge, corresponding to the main judgment criterion.

RESULTS

If we consider only the end zones of the osteotomy cut, regardless of its angulation with respect to the JL, the zone which presents, on average, the lowest local stress concentration is the AM zone (40.3MPa). If we consider only the angulation of the osteotomy cut, with respect to the JL, regardless of the end zone of the cut, the angulation that locally concentrates, on average, the least stress is an angulation at 10° (147.7MPa). Finally, it is important to define the best end zone of the osteotomy cut for each angulation value in relation to the JL: for an angulation of 10°, the end zone must be in AM (38MPa), but also for an angulation of 15° (45MPa), and for an angulation of 20° (38MPa).

DISCUSSION-CONCLUSION

With the inherent caveats of the experimental conditions, the hypothesis is confirmed. An end zone of the osteotomy cut exists (AM) and an orientation (10°) that induces the lowest local stress concentration and therefore the least likely to induce lateral hinge fracture. However, the orientation of the osteotomy cut is also a matter of surgical habit, especially regarding complementary osteotomy of the tibial tuberosity that some may want to avoid. Thus, it is equally important to know the best end zone associated with a given angulation of the cut in relation to the JL, which according to these results is the AM zone for each angulation. This information helps guide the operator in their surgical practices according to their habits.

LEVEL OF EVIDENCE

V, expert opinion.

Risk Factor Analysis for Infection after Medial Open Wedge High Tibial Osteotomy

Background: Medial open wedge high tibial osteotomy (MOWHTO) is a well-established treatment for osteoarthritis of the medial tibiofemoral compartment. Surgical site infection (SSI) after MOWHTO is a devastating complication that may require further surgery. In this study, we aimed to identify the risk factors for infection after MOWHTO over 1 to 4 years of follow-up. Methods: Fifty-nine patients who underwent MOWHTO combined with knee arthroscopic surgery were included in this prospective study. Artificial bone grafts were used in all cases. Possible risk factors, including sex, age, body mass index (BMI), underlying disease, hospitalization length, correction angle, and surgery time, were recorded. Both univariate and multivariate analysis were used. Results: A total of 59 patients who underwent 61 operations were included. Eleven patients (18.0%) were reported to have SSI. Univariate analysis showed that smoking and diabetes mellitus were positively associated with SSI. Multivariate analysis showed that smoking and age were positively associated with SSI. Three patients (4.9%) were reported to suffer from deep SSI, requiring surgical debridement, all of whom were male smokers. Conclusion: Smoking, diabetes mellitus, and old age were identified to be possible risk factors of SSI after MOWHTO. These findings are common risk factors of SSI after orthopedic surgery according to the literature. Patient selection should be performed cautiously, and postoperative prognosis for MOWHTO should be carefully explained to patients who smoke.

The degree of correction in open-wedge high tibial osteotomy compromises bone healing: A consecutive review of 101 cases

BACKGROUND

The bone healing in open-wedge high tibial osteotomy (OWHTO) proceeds gradually by a filling of the osteotomy gap. This can comprise several risk factors.

METHODS

A retrospective study analysed the clinical and radiological course of 101 consecutive OWHTOs in 96 patients. The following risk factors were considered: age, body mass index, tobacco consumption, amount of tobacco consumption, severity of comorbidities, infection of the surgical area, occurrence of a lateral hinge fracture and the degree of correction. The bone healing was evaluated by using the modified Radiographic Union Score for Tibial fractures (RUST).

RESULTS

A disturbance in bone healing was observed in 16 of the 101 osteotomies. Binary logistic regression analysis showed a correlation between the angle of the opening wedge and the development of a disturbance in bone healing (P = 0.002). The odds ratio indicated an increase in the risk of a disturbance in bone healing of 56% with each additional degree of correction. For the risk factor 'age' a statistical trend was recognizable (P = 0.077) with the risk of a disturbance in bone healing in higher age.

CONCLUSION

Lateral hinge fractures seem not to have a detrimental effect on the filling of the osteotomy gap. An increase in the opening wedge bears the risk of a disturbance in bone healing.

Biomechanical evaluation of different types of lateral hinge fractures in medial opening wedge high tibial osteotomy

BACKGROUND

Lateral hinge fractures are common complications in the medial opening wedge high tibial osteotomy for treatment of knee osteoarthritis. The rehabilitation protocols are decided depending on the remaining stability following these fractures. This study aimed to evaluate the biomechanical properties of different types of lateral hinge fractures in medial opening wedge high tibial osteotomy.

METHODS

Twenty synthetic tibia models were used as test samples. A 10-mm bone wedge was removed from the medial side of the proximal tibias to create the bone defect. The samples were then divided into 4 groups: (1) intact lateral hinge; (2) Takeuchi type I fractures; (3) type II fractures; and (4) type III fractures. After fixation with a locking plate, the stability parameters including construct stiffness, wedge displacement, and construct strength were tested under compressive forces and compared among the 4 groups.

FINDINGS

No statistical difference was found in the construct stiffness among the 4 groups (P = 0.78). The type III fractures had the largest wedge displacement compared with the other 3 groups. The failure loads on average were significantly reduced in the type III fractures compared with those with intact hinge (P < 0.01) and in type I fractures (P = 0.04). No statistical difference was observed between the type I fractures and the intact hinge in terms of wedge displacement or failure loads.

INTERPRETATION

The type III fractures were the most unstable and patients with these fractures should be managed cautiously. Delayed weightbearing and/or additional fixation should be considered.

Arthroscopic double-button Latarjet: two-thirds of bone block healed at 90 days

PURPOSE

The aim of this study was to evaluate the union rate and risk factors for delayed union in the early postoperative period after an arthroscopic Latarjet with double-button fixation.

METHOD

In a retrospective study, postoperative CT scans at 3 months were analysed following an arthroscopic Latarjet with double-button fixation used to treat anterior shoulder instability. Healing of the bone block, its position in the sagittal and coronal planes, and the contact area graft/scapula were analysed.

RESULTS

Ninety-eight CT scans (98 patients) were included. The rate of healing at 3 months was 63/98 (64%) and four grafts clearly migrated. The position was perfectly flush to the glenoid rim in 67% and under the equator in 96%. The mean contact graft/scapula area was 135 mm 2 (4-420). In multivariate analysis, the risk of non-union at 3 months was associated with tobacco consumption (p = 0.001, aOR = 12.17 95% CI [2.62-56.49]), absence of preoperative glenoid bone defect (p = 0.003, aOR = 8.06 95% CI [2.06-31.56]), and a contact area graft/scapula less than 120 mm 2 (p = 0.010, aOR = 5.25 95% CI [1.50-18.40]). Among 31 non-united grafts, 93% definitively healed on CT scan at 1 year, leaving an overall rate of 93% of united grafts at last follow-up.

CONCLUSIONS

The rate of union at 3 months after an arthroscopic Latarjet with double-button fixation was 64%, reaching 93% at 1 year. This procedure should be carefully indicated in case of tobacco use or instability without glenoid bone defect, especially when the shoulder is exposed to high-energy trauma in the early phase after surgery.

Radiographic Humerus Union Measurement (RHUM) Demonstrates High Inter- and Intraobserver Reliability in Assessing Humeral Shaft Fracture Healing

BACKGROUND

Orthopedic surgeons use radiographs to determine degrees of fracture healing, guide progression of clinical care, and assist in determining weight bearing and removal of immobilization. However, no gold standard exists to determine the progression of healing of humeral shaft fractures treated non-operatively.

PURPOSE

The purpose of this study was to determine whether a scale comparable to the modified Radiographic Union Score for Tibial (RUST) fractures applied to non-operatively treated humeral shaft fractures can increase interobserver reliability in determining fracture healing.

METHODS

A retrospective review was undertaken by three orthopedic traumatologists and one musculoskeletal radiologist, who evaluated 50 sets of anteroposterior and lateral radiographs, presented at random, of non-operatively treated humeral shaft fractures at various stages of healing from 17 patients. The radiographs were scored using a modified RUST scale called the Radiographic Humerus Union Measurement (RHUM). Observers were blinded to the time from injury. After a 4-week washout period, observers again scored the same radiographs. Observers classified each fracture as either healed or not healed based on the combination of radiographs. Inter- and intraobserver reliability of the RHUM were determined using an intraclass correlation coefficient (ICC). Interobserver reliability of determining a healed fracture was calculated using Cohen's kappa (κ) statistics. A receiver operator characteristic curve was conducted to determine the RHUM score predictive of a fracture being considered healed.

RESULTS

ICC demonstrated almost perfect interobserver reliability (ICC, 0.838; ICC 95% CI, 0.765 to 0.896) and intraobserver reliability (ICC range, 0.822 to 0.948) of the RHUM. κ demonstrated substantial agreement between observers in considering a fracture healed (κ = 0.647). Receiver operating characteristic (ROC) curve demonstrated that a RHUM of 10 or higher is an excellent predictor of the observer considering the fracture healed (area under the ROC curve = 0.946, specificity = 0.957, 95% CI specificity, 0.916 to 0.979).

CONCLUSIONS

This cortical scoring system has excellent interobserver reliability in humeral shaft fractures treated non-operatively. Consistent with previous cortical scoring systems, a RHUM score of 10 or above can be considered radiographically healed.

Treatment of aseptic nonunion after medial opening-wedge high tibial osteotomy

BACKGROUND

Nonunion after medial opening-wedge high tibial osteotomy (OWHTO) is a rare but serious complication with very limited data regarding its treatment. The aim of this study was to analyze the healing rate after operative treatment of nonunion after OWHTO.

METHODS

We performed a single-center, retrospective study that included 14 patients with nonunion after OWHTO between 2010 and 2018. The treatment for all patients consisted of local debridement and cancellous bone grafting at the osteotomy gap. Revision osteosynthesis due to a loss of correction/loosening of the locking screws or plates was performed in 5 patients. In 7 patients, lateral hinge fractures were treated with additional lateral plating. Union was confirmed using the modified "Radiographic Union Score for Tibial fractures". Outcome measure was the Lysholm Knee Score at final follow-up.

RESULTS

The mean age of the patients included in our study was 48.4 ± 6.7 years. Three patients were female (21.4%). The mean follow-up period was 20.8 ± 12.8 months. Union was achieved in 12/14 patients (85.7%) after a mean of 6 months (range, 3-13). The mean Lysholm Knee Score at the final follow-up was 83.2 ± 11.6. Two patients did not reach definitive union during the follow-up. In one patient, an infection of the nonunion following bone grafting was successfully treated with a two-stage procedure. Two patients needed additional cancellous bone grafting 6 and 8 months after the first revision surgery. All patients showed pain-free full weight bearing after union was achieved.

CONCLUSIONS

Nonunions after OWHTO can generally be treated successfully with cancellous bone grafting. For patients who have loss of correction, loosening of the osteosynthetic material or fracture of the lateral hinge, an additional revision or additive osteosynthesis may be required.

LEVEL OF EVIDENCE

Grade III.

Dome-shaped high tibial osteotomy with semi-circular Ilizarov pin fixator: Mid- to long-term results of a novel technique

BACKGROUND

The aim of this study was to assess the clinical and radiological results of the dome-shaped high tibial osteotomy (HTO) which was fixed with a novel construct comprised of semi-circular Ilizarov frames and pins.

METHODS

The patients with at least five years of follow-up were evaluated. One-hundred and thirty-two knees of 114 patients were included in the final analysis. The clinical evaluation included range of motion and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score. Anatomical femorotibial angle (aFTA), anatomical medial proximal tibial angle (aMPTA), tibial slope and Insall-Salvati ratio were calculated on standard weight-bearing radiographs.

RESULTS

The average aFTA was improved from 1.6° varus to 8.7° valgus (P < 0.001). The average WOMAC score (P < 0.001) and flexion value (P = 0.014) were improved at the latest follow-up (WOMAC: 17.2, flexion: 142.5) compared with the preoperative period (WOMAC: 59.6, flexion: 129.2). The sagittal radiological parameters were not significantly affected. The five-year survival was 96.2%, and 10-year survival was 83.3%.

CONCLUSIONS

The semi-circular Ilizarov pin construct provided satisfactory outcomes both clinically and radiologically at mid- to long-term follow-up.

Complications, Additional Surgery, and Joint Survival Analysis After Medial Open-Wedge High Tibial Osteotomy

The reported incidence of complications following medial open-wedge high tibial osteotomy (MOWHTO) varies. The authors sought to assess the complications, additional surgeries, and joint survival following MOWHTO in patients with isolated medial compartment arthrosis during a mean follow-up of 10 years. This retrospective study involved patients implanted with spacer plates, angle adjustable plates, or inverse L-type plates with wedges between 2000 and 2010. A total of 504 knees from 441 patients were examined. Mean age of the study population was 52.6±7.0 years, with 56 (11.1%) knees from men and 448 (88.9%) from women. The 10-year Kaplan-Meier joint survival rate was 94.8%. Overall complication rate for MOWHTO was 63.7%, with complications in 20.3% of treated knees requiring additional surgery. In this population, although the overall complication rate and the need for additional surgery were high, the need for additional surgery resulting from serious complications was low (2.6%). The high joint survival rate and low rate of additional surgery for serious complications indicate that MOWHTO can be safely applied in patients with isolated medial gonarthrosis. [Orthopedics. 2020;43(5):303-314.].

Reliability of RUST and Modified RUST Scores for the Evaluation of Union in Humeral Shaft Fractures Treated with Different Techniques

BACKGROUND

The study aimed to evaluate the agreement between the radiographic union scale (RUST) and modified RUST (mRUST) in humeral shaft fractures treated with different techniques, and the effect of surgeons' experience and thresholds for determining bone union.

MATERIALS AND METHODS

A total of 20 orthopedic surgeons reviewed and scored radiographs of 30 patients with humeral shaft fractures treated by external fixation, intramedullary nailing, and plating using the RUST and mRUST on the 0 day, 6 weeks, 12 weeks and 24 weeks follow-up radiographs. Bone healing, interrater agreement between RUST and mRUST scores, and the threshold for radiographic union were evaluated.

RESULTS

The intraclass correlation coefficient (ICC) was slightly higher for the mRUST score than the RUST score (0.71 versus [vs.] 0.67). There was substantial agreement between the mRUST and RUST scores for external fixation (0.75 and 0.69, respectively) and intramedullary nailing (0.79 and 0.71); there was moderate agreement between them for plating (0.59 and 0.55). Surgeons with varying experience had a similar agreement for both scores and scores for each humeral cortex. The external fixation and intramedullary nailing group had higher RUST and mRUST scores than the plating group. The ICC for union was substantial (0.64; external fixation: 0.68, intramedullary nailing: 0.64, and plating: 0.61). More than 90% of the reviewers recorded scores of 10/12 for RUST and 13/16 for mRUST at the time of union.

CONCLUSIONS

RUST and mRUST scores can be used reliably for the evaluation of bony union in humeral fractures treated with an external fixator and intramedullary nailing. In cases of humeral plating, a more sensitive tool for evaluation of fracture union is needed.

Total knee arthroplasty in achondroplasia without deformity correction: A case report with 11 years' follow-up

Knee osteoarthritis in patients with achondroplasia is rare. Bowleg deformity is typical but corrective surgery is limited. Thus, primary total knee arthroplasty (TKA) might be challenging due to the particular anatomy. We report on a patient with 11 year's follow-up after a TKA performed maintaining bowleg alignment, using a posterior stabilized, fixed-bearing design. Sequential X-rays showed radiolucencies on the femoral component within two years postoperatively, slightly increasing over time but stable at last follow-up. The Oxford Knee Score showed an excellent result at 11 years. Despite the peculiarities of a case report, TKA without concomitant osteotomies might be an option for such patients. Nevertheless, a thorough discussion about pros and cons is paramount.

Day-Case Opening Wedge High Tibial Osteotomy With Intraosseous PEEK Implant

Purpose

To evaluate the short-term clinical outcomes, complications, hospitalization time, and readmission rate related to day-case opening wedge high tibial osteotomy (OWHTO) with intraosseous PEEK (polyether ether ketone) implant, in the treatment of knee osteoarthritis.

Methods

An observational study on patients treated with OWHTO using intraosseous PEEK implant was performed with a period of 12 months follow-up. Grade of Knee Injury and Osteoarthritis Outcome Score (KOOS) was assessed preoperatively, at 6 months, and at 12 months postoperatively. A simple t test was used to analyze the outcomes. P values <.05 were considered significant. Complications and revision surgeries were registered.

Results

In the period from 2016 to 2017, a consecutive group of 40 patients (13 female, 27 male) with symptomatic medial knee osteoarthritis and varus malalignment were included in the study. The average age of the patients was 54.9 (± 7.6) years. In total, 30 (77%) patients met the criterion for minimal clinically important difference in KOOS scores. The KOOS symptoms improved from 58.1 ± 20 to 78.5 ± 16.5 (P < .0001), pain from 48.1 ± 18.2 to 78.6 ± 18.5 (P < .0001), activities of daily living from 59.0 ± 19.5 to 84.1 ± 15.2 (P < .0001), sport from 23.2 ± 17.6 to 55.6 ± 26.3 (P < .0001), and quality of life from 28.4 ± 12.8 to 61.5 ± 22.5 (P < .0001) at 1-year follow-up. The average hospitalization time at the Day Surgery Unit was 5.6 ± 0.7 hours, and 4 (10%) patients had to be readmitted to the hospital within 2 weeks postoperatively. The overall complication rate was 18%. Complications that required revision surgery were registered in 4 patients (10%), including 2 non-unions and 2 progressions of osteoarthritis.

Conclusions

The day-case OWHTO with intraosseous PEEK implant was a success in 77% of the cases. The results and complications were comparable with other published studies. Despite a short hospitalization time, the readmission rate was low.

Level of Evidence

IV, therapeutic case series.

The efficacy of porous hydroxyapatite chips as gap filling in open-wedge high tibial osteotomy in terms of clinical, radiological, and histological criteria

PURPOSE

Hydroxyapatite (HA) does not fully degrade, which raises concerns about poor remodeling and incorporation into the bone after open-wedge high tibial osteotomy (HTO). The purpose of this study was to compare the results between gap filling with allogenous chip bone and HA chip after open-wedge HTO using propensity score matching and to analyze the radiological unabsorbed area of opening gaps histologically in HA using patients.

METHODS

The matched variables were age, body mass index, sex, correction angle, and smoking status. After matching, the allogenous group and HA group included 33 patients each with two years of follow-up. The range of motion (ROM), International Knee Documentation Committee (IKDC) subjective score, Knee Injury and Osteoarthritis Outcome Score (KOOS), mechanical axis (MA), tibial slope, osteoconductivity, and absorbability were evaluated and compared between both groups. Among the HA group, 20 patients underwent bone biopsy and histologically analyzed of the radiological unabsorbed area.

RESULTS

The postoperative ROM, IKDC subjective score, and KOOS were similar in both groups. The osteoconductivities did not differ significantly. The absorbability in the HA group was significantly lower than allogenous group (59.6% vs. 22.6%, P < .001). The histological sections of the radiological unabsorbed area showed mature lamelliform bone tissues were significantly greater than structurally degraded remnant HA (30.4% and 4.2%, P < .001).

CONCLUSION

The HA chips showed an inferior absorbability, however, a mature lamelliform bone was observed in significantly larger amounts than remnant HA in the radiological unabsorbed area. The allogenous bone chips and HA chips showed similar clinical and radiological results after open-wedge HTO.

Corrective osteotomies of femur and tibia: which factors influence bone healing?

INTRODUCTION

Corrective osteotomies of the lower limb are standard procedures in orthopedic surgery. Still, there is only limited research on factors affecting bone healing after osteotomies. We hypothesize that especially the location of the osteotomy, smoking status and BMI affect bone healing.

MATERIAL AND METHODS

The healing process of 547 patients who underwent osteotomies of the lower limb (259 female, 288 male; average 40.6 years, range 14-77) was evaluated. To assess bone healing, participants were divided into three groups by bone healing duration ( < 5/5-8/ > 8 months). Differences in healing duration related to the anatomic level of the osteotomy (diaphysis vs. metaphysis), age, gender, smoking status, BMI, and modus of the osteotomy (open vs. closed wedge) were tested for significance using an ordinal regression analysis.

RESULTS

A significant correlation between bone healing and the anatomical level of the osteotomy on femur and tibia and the patients' smoking status was found. The odds of the diaphysis considering bone healing was 0.187 (95% CI, 0.08-0.44) times that of the metaphysis (Wald χ²(1) = 14.597, p < 0.000). The odds ratio of smokers considering bone healing was 0.192 (95% CI, 0.11-0.33) times that of non-smokers (Wald χ²(1) = 35.420, p < 0.000). All other analyzed factors did not show a significant correlation with bone healing.

CONCLUSIONS

Smoking status and the localization of the osteotomy on femur and tibia (diaphysis vs. metaphysis) are significantly correlated with bone healing duration. In line with current literature emphasizing the detrimental effect of smoking on bone healing, our findings should encourage surgeons to think twice about the indication to perform osteotomies on smokers. Furthermore, if applicable, osteotomies should be performed in the metaphyseal areas of femur and tibia.

Distal radius correction osteotomy with tricortical bone graft is a successful method in heavy smokers

BACKGROUND

Corrective osteotomy is a technically challenging surgical option to improve wrist function in tilted distal radius malunions. However fracture healing in smokers is adversely affected. The aim of this study was to evaluate the clinical and radiological effect of cigarettes on bone union in heavy-smokers who underwent corrective osteotomy with a triangular bone graft harvested from the iliac crest.

METHOD

Fifteen patients, who were treated using trapezoidal block grafts taken from the iliac crest, who were smokers of 20 or more cigarettes daily (heavy smokers) with no chronic disease, and who consented to participate in the study. Fifteen non-smoker patients of the same age group were determined as the control group. Radiological measurements were made to include radial inclination and ulnar variance in pre-operative and post-operative radiographs. Functional evaluation was performed using Q-DASH and MAYO hand-wrist scores.

RESULTS

In both groups, the mean age of the patients was 49,1 ± 3,92 years. Smokers group the bone union in the osteotomy line was observed after 16,63 (12-24 h) weeks, non-smokers grup 14.1 (12-24) weeks (p = 0.06). Range of motion is found similar clinic between in groups (p > 0.05). Q-DASH for group smokers was 17.54 ± 1.85, nonsmokers 17.20 ± 1.24 (p = 0,878); MAYO was 82.27 ± 6.06 for 82.00 ± 7.74 (p = 0.874). for group B. No statistically significant difference was noted between the groups.

CONCLUSION

Our study showed that cigarette smoking did not have negative effect on union time in the metaphyseal region after correction osteotomy. The time of bone-union in heavy-smokers was 2.5 weeks more than that of non-smokers.

Biomechanical effect of a lateral hinge fracture for a medial opening wedge high tibial osteotomy: finite element study

BACKGROUND

This study aimed to investigate the biomechanical effect on the Takeuchi classification of lateral hinge fracture (LHF) after an opening wedge high tibial osteotomy (HTO).

METHODS

We performed an FE simulation for type I, type II, and type III in accordance with the Takeuchi classification. The stresses on the bone and plate, wedge micromotion, and forces on ligaments were evaluated to investigate stress-shielding effect, plate stability, and biomechanical change, respectively, in three different types of LHF HTO and with the HTO without LHF model (non-LHF) models.

RESULTS

The greatest stress-shielding effect and wedge micromotion were observed in type II LHF (distal portion fracture). The type II and type III (lateral plateau fracture) models exhibited a reduction in ACL force and an increase in PCL force compared with the HTO without LHF model. However, the type I (osteotomy line fracture) and HTO without LHF models did not exhibit a significant biomechanical effect. This study demonstrates that Takeuchi type II and type III LHF models provide unstable structures compared with the type I and HTO without LHF models.

CONCLUSIONS

HTO should be performed while considering a medial opening wedge HTO to avoid a type II and type III LHF as a potential complication.

Scoring of radiographic cortical healing with the radiographic humerus union measurement predicts union in humeral shaft fractures

PURPOSE

The purpose of this study is to determine if the radiographic humerus union measurement (RHUM) is predictive of union in humeral shaft fractures treated nonoperatively.

METHODS

All patients with long bone fracture nonunion presenting to a single surgeon were enrolled in a prospective registry. This registry was queried to identify patients with humeral shaft fractures treated nonoperatively and developed nonunion. The nonunion cohort was matched to a three to one gender- and age-matched control group that were treated nonoperatively for a humeral shaft fracture and achieved union. Two fellowship-trained orthopedic traumatologists blinded to eventual union scored radiographs obtained 12 weeks after injury using the RHUM. A binomial logistic regression determined the effect of the RHUM on the likelihood of developing union.

RESULTS

Nine patients with humeral shaft fractures treated nonoperatively with radiographs 12 weeks after injury that developed nonunion were identified. These patients were matched to 27 controls. Logistic regression demonstrated the RHUM was a significant predictor of healing 12 weeks after humeral shaft fracture treated nonoperatively (p = 0.014, odds ratio 9.434, 95% CI for OR 1.586-56.098). All patients with RHUM below 7 went on to nonunion. All patients with RHUM above 8 healed. Three of seven patients (43%) with RHUM of 7 or 8 healed.

CONCLUSION

The RHUM demonstrated an increased likelihood of achieving union 12 weeks after injury. Orthopedic surgeons can counsel patients that fractures with RHUM scores of 6 or below are in danger of developing nonunion and can target interventions appropriately.

Lateral hinge fracture delays healing of the osteotomy gap in opening wedge high tibial osteotomy with a beta-tricalcium phosphate block

BACKGROUND

The purpose of this study was to investigate the healing process of synthetic bone grafts in opening wedge high tibial osteotomy (OWHTO) and to identify the factors that affect bone healing in OWHTO. It was hypothesized that lateral hinge fracture (LHF) is associated with delayed bone healing after OWHTO with synthetic bone grafting.

METHODS

The subjects included 350 knees of 283 patients who underwent OWHTO using two wedged blocks of beta-tricalcium phosphate (β-TCP) with 60% porosity. The healing of the osteotomy gap using a radiologic rating system for OWHTO with synthetic bone grafts and the presence of an LHF were assessed up to postoperative 24 months.

RESULTS

LHFs were found in 49 knees (14%). The osteotomy gap showed slower progression of radiographic healing with an LHF than without an LHF (P < .05). In the knees with LHFs, initial radiographic change in the osteotomy gap was observed almost at the same time as healing of the LHF. Multivariate logistic regression analysis identified LHF as the factor preventing the progression of bone healing (OR = 46.78, P < .05).

CONCLUSIONS

LHF is associated with delayed bone healing after OWHTO with synthetic bone grafting.

Factors affecting stability after medial opening wedge high tibial osteotomy using locking plate: A cadaveric study

OBJECTIVES

To investigate the effect of screw length, lateral hinge fracture, and gap filling on stability after medial opening wedge high tibial osteotomy (MOW HTO) using a locking plate.

METHODS

Forty tibiae from fresh-frozen cadavers were randomly allocated into five groups. Group A was bicortically fixated, while Group B and Group C were unicortically fixated: 90% and 55% of drilled tunnel length, respectively. Group D was fixated using 90% length screws with a fractured lateral hinge. Group E was fixated using 90% length screws with gap filling using a bone substitute. Operated tibiae were tested under axial compressive load using a material testing machine. The medial gap changes under the serial axial load of 100-600 N and ultimate failure load were measured.

RESULTS

Group D showed the biggest medial gap change and lowest failure load, while Group E presented the smallest gap change and highest failure load. The medial gap changes tended to increase with shorter screw length, but the difference was not significant between Groups A, B, and C. Group C and Group D showed greater medial gap change and lower failure load compared with Group E, while not differing from Group A and Group B.

CONCLUSIONS

Unicortical fixation in proximal screw holes of a locking plate was not inferior to bicortical fixation regarding axial stability in MOW HTO, although proximal screws that are too short should be avoided. Lateral hinge fracture decreased, while gap filling with bone substitute increased axial stability.

Effect of saw blade geometry on crack initiation and propagation on the lateral cortical hinge for HTO: Finite element analysis

INTRODUCTION

The hinge plays a primary role in the hold and healing of a high tibial osteotomy (HTO). Weakening of the hinge is a risk factor for failure. The aim of our study was to determine whether the geometry of the saw blade's cutting edge impacts crack initiation or propagation on the hinge.

HYPOTHESIS

A certain cutting edge geometry exists that will reduce this risk.

MATERIALS AND METHODS

A finite element model with transverse isotropic elastic bone properties was created. A 1.27-mm thick saw cut (full thickness in anteroposterior direction) was made leaving a 1cm lateral cortical hinge. Three different cutting edge geometries were compared: rectangular, U-shaped, V-shaped. Opening of the osteotomy was done over 1mm for 1 s by a load applied distally with the proximal portion fixed. In the first simulation, no crack was initiated at the hinge, while in the second simulation, the beginnings of a 2mm crack angled upward at 15° was added. These two simulations were used to identify whether a local stress riser was present at the hinge. This information was used to calculate the energy release rate to the hinge, which corresponds to the energy needed to initiate and propagate a crack on the hinge.

RESULTS

In the first simulation (no crack initiation), a rectangular saw blade geometry resulted in the lowest local stress concentration. In the second simulation (with crack initiation), the U-shaped geometry resulted in the lowest local stress concentration. The U-shaped geometry had the lowest energy release rate, meaning that it was the least likely to initiate and propagate a crack on the lateral cortical hinge.

DISCUSSION/CONCLUSION

Keeping the inherent limitations related to computer modelling in mind, our findings show that a U-shaped cutting edge is least likely to initiate or propagate a crack since it has the lowest energy release rate. This confirms our hypothesis.

LEVEL OF EVIDENCE

V, expert opinion.

Opposite cortical fractures in closed-wedge HTO: New classification and treatment algorithm

BACKGROUND

An intact opposite cortex (OC) is essential for HTO stability. For an appropriate prognosis of the role of opposite cortical fracture (OCF) in the development of mechanical complications, it is important to identify the type of OCF. This study seeks to establish an OCF classification in CWHTO with a treatment algorithm.

METHODS

The clinical radiological results of 187 angle-stable navigated CWHTOs were retrospectively analyzed. Two OCF types (according the direction of fracture line) with three subtypes (A-nondisplaced, B-primarily, and C-secondarily displaced) were identified.

RESULTS

A total of 67.6% of type 1 and 44.7% of type 2 OCFs were non-displaced (p = 0.041). Secondary displacement developed in 36.2% of type 2 OCFs and in none of the type 1 OCFs. The tibial pseudoarthrosis rate was significantly higher with displaced type 2B and 2C OCFs than with non-displaced 2A fractures (30.8% vs. 4.8%, p = 0.03). The regression analysis showed a relevant correlation between OCF types 1B, 2B, and 2C and the incidence of mechanical complications; the significance of type 2C fractures (OR 43.8) for the incidence of tibial pseudoarthrosis was more than twice as high than for type 1B fractures.

CONCLUSION

Type 1 OCFs are considered to be stable and type 2 OCFs unstable with a tendency to become displaced. Only 57.4% of type 2 OCFs were recognizable intraoperatively; thus, increased attention must be focused on this event in postoperative repeat radiographs. The classification provides practice-relevant therapeutic approaches.

Opposite hinge fractures in high tibial osteotomy: a displacement subtype is more critical than a fracture type

PURPOSE

Analysis of the structure of the fractures of opposite hinge (FOH) after angle-stable closed-wedge (CW) and open-wedge (OW) high tibial osteotomy (HTO), and their influence on the development of tibial pseudarthrosis.

METHODS

187 CW and 94 OWHTOs were analyzed retrospectively. The FOHs in the OWHTO were classified according to Takeuchi, and in the CWHTO-according to the own classification with two types (depending on the direction of FOH). FOHs in both techniques were also subdivided into three subtypes according to displacement (A-non-displaced, B-primarily displaced, C-secondarily displaced). The statistical analysis included correlation analysis and logistic regression.

RESULTS

FOHs were found in 81 (43.3%) CW and 39 (41.2%) OWHTOs. The stable type 1 fractures predominated in OWHTO (76.9 vs. 42%, p < 0.001), the unstable type 2 FOHs prevailed in CWHTO (58 vs. 17.9%, p < 0.001). The tibial pseudarthrosis rate was higher with type 1 (20 vs. 12.9%, n.s.) and subtype A (16.7 vs. 6.8%, p = 0.048) FOHs in OWHTO, and with type 2 (20 vs. 0%, p < 0.001) and subtypes B (25 vs. 0%, p < 0.001) and C (29.4 vs. 25%, n.s.) in CWHTO (without FOHs 0.9% in CW and 1.8% in OWHTO, n.s.). Relevant correlations were detected between the pseudarthrosis rate and fracture type only in CWHTO (ρ_s = 0.298, p < 0.001, OR 24.87 for type 2) and displacement subtype in both groups (for subtype C: ρ_s = 0.345, p < 0.001, OR 43.75 and ρ_s = 0.231, p = 0.02, OR 18.0, respectively).

CONCLUSIONS

The unstable FOH types were more common in CWHTO. The displacement subtype was more predictive for the development of tibial pseudarthrosis than the fracture type, especially in OWHTO. The secondarily displaced FOHs (subtype C) represented the highest risk for the occurrence of pseudarthrosis in both techniques.

Virtual Mechanical Testing Based on Low-Dose Computed Tomography Scans for Tibial Fracture: A Pilot Study of Prediction of Time to Union and Comparison with Subjective Outcomes Scoring

BACKGROUND

Quantitative outcomes assessment remains a persistent challenge in orthopaedic trauma. Although patient-reported outcome measures (PROMs) and radiographic assessments such as Radiographic Union Scale for Tibial Fractures (RUST) scores are frequently used, very little evidence has been presented to support their validity for measuring structural bone formation or biomechanical integrity.

METHODS

In this pilot study, a sequential cohort of patients with a tibial shaft fracture were prospectively recruited for observation following standard reamed intramedullary nailing in a level-I trauma center. Follow-up at 6, 12, 18, and 24 weeks included radiographs and completion of PROMs (EuroQol 5-Dimension [EQ-5D] and pain scores). Low-dose computed tomography (CT) scans were also performed at 12 weeks. Scans were reconstructed in 3 dimensions (3D) and subjected to virtual mechanical testing via the finite element method to assess torsional rigidity in the fractured limb relative to that in the intact bone.

RESULTS

Patients reported progressive longitudinal improvement in mobility, self-care, activity, and health over time, but the PROMs were not correlated with structural bone healing. RUST scoring showed moderate intrarater agreement (intraclass coefficient [ICC] = 0.727), but the scores at 12 weeks were not correlated with the time to union (R = 0.104, p = 0.193) and were only moderately correlated with callus structural integrity (R = 0.347, p = 0.010). In contrast, patient-specific virtual torsional rigidity (VTR) was significantly correlated with the time to union (R = 0.383, p = 0.005) and clearly differentiated 1 case of delayed union (VTR = 10%, union at 36 weeks) from the cases in the normally healing cohort (VTR > 60%; median union time, 19 weeks) on the basis of CT data alone.

CONCLUSIONS

PROMs provide insight into the natural history of the patient experience after tibial fracture but have limited utility as a measure of structural bone healing. RUST scoring, although reproducible, may not reliably predict time to union. In contrast, virtual mechanical testing with low-dose CT scans provides a quantitative and objective structural callus assessment that reliably predicts time to union and may enable early diagnosis of compromised healing.

LEVEL OF EVIDENCE

Therapeutic Level IV. Please see Instructions for Authors for a complete description of levels of evidence.

Inter-Rater Reliability of the Modified Radiographic Union Score for Diaphyseal Tibial Fractures With Bone Defects

OBJECTIVES

To evaluate inter-rater reliability of the modified Radiographic Union Score for Tibial (mRUST) fractures among patients with open, diaphyseal tibia fractures with a bone defect treated with intramedullary nails (IMNs), plates, or definitive external fixation (ex-fix).

DESIGN

Retrospective cohort study.

SETTING

Fifteen-level one civilian trauma centers; 2 military treatment facilities.

PATIENTS/PARTICIPANTS

Patients ≥18 years old with open, diaphyseal tibia fractures with a bone defect ≥1 cm surgically treated between 2007 and 2012.

INTERVENTION

Three of 6 orthopedic traumatologists reviewed and applied mRUST scoring criteria to radiographs from the last clinical visit within 13 months of injury.

MAIN OUTCOME MEASUREMENTS

Inter-rater reliability was assessed using Krippendorff's alpha (KA) statistic; intraclass correlation coefficient (ICC) is presented for comparison with previous publications.

RESULTS

Two hundred thirteen patients met inclusion criteria including 115 IMNs, 24 plates, 29 ex-fixes, and 45 cases that no longer had instrumentation at evaluation. All reviewers agreed on the pattern of scoreable cortices for 90.4% of IMNs, 88.9% of those without instrumentation, 44.8% of rings, and 20.8% of plates. Thirty-one (15%) cases, primarily plates and ex-fixes, did not contribute to KA and ICC estimates because <2 raters scored all cortices. The overall KA for the 85% that could be analyzed was 0.64 (ICC 0.71). For IMNs, plates, ex-fixes, and no instrumentation, KA (ICC) was 0.65 (0.75), 0.88 (0.90), 0.47 (0.62), and 0.48 (0.57), respectively.

CONCLUSIONS

In tibia fractures with bone defects, the mRUST seems similarly reliable to previous work in patients treated with IMN but is less reliable in those with plates or ex-fixes, or after removal of instrumentation.

Medial Open-wedge Osteotomy with Double-plate Fixation for Varus Malunion of the Distal Femur

Objective

To present our clinical experience of treating varus malunion of the distal femur through a medial open‐wedge osteotomy with double‐plate fixation.

Methods

A prospective cohort study was performed. From January 2005 to February 2015, 15 consecutive patients with varus malunion following distal femur fractures were surgically treated at a single level I trauma center. The coronal and sagittal deformity were corrected by a medial open‐wedge osteotomy of the distal femur. A medial buttress plate was used to maintain the realignment. A lateral locking plate was additionally used as a protection plate. The mean age of patients at the time of the surgery was 35.5 years (range, 22–58 years). The radiographical evaluation included the mechanical femorotibial angle, the mechanical lateral distal femoral angle, the anatomic posterior distal femoral angle, and the leg length discrepancy. Clinical outcome evaluation consisted of the range of motion (ROM) and Hospital for Special Surgery (HSS) score.

Results

Mean follow‐up was 7.4 years (range, 4–11.5 years). Varus and flexion malalignment and limb discrepancy were adequately corrected in all patients. The mechanical femorotibial angle, the mechanical lateral distal femoral angle, and the anatomic posterior distal femoral angle were restored from 17.5° (range, 13°–25°) to 2.3° (range, − 2°–7°), 102.3° (range, 95°–112°) to 85.2° (range, 81°–92°), and 77.1° (range, 65°–87°) to 82.7° (range, 76°–88°), respectively. The leg length discrepancy was diminished from 3.4 cm (range, 2.4–4.5 cm) to 0.8 cm (range, 0–1.7 cm). The average bone healing time was 4.1 months (range, 2.5–6 months). The average ROM of the affected knees at 24‐month follow‐up was 3.4°–112.55°. The score of HSS at 4‐years follow‐up was 76.1 (range, 64–88). No internal fixation failure or secondary operation was noted until the last follow‐up.

Conclusion

Medial open‐wedge osteotomy can adequately correct the posttraumatic varus malunion of the distal femur. With fixation of the double plate, non‐displaced bone healing and good functional outcome are expected.

Radiographic union score for tibia fractures predicts success with operative treatment of tibial nonunion

BACKGROUND

The purpose of this study is to evaluate the ability of preoperative and postoperative radiographic union scores for tibia fractures (RUST) to predict treatment success of tibia fracture nonunion.

MATERIALS AND METHODS

Patients presenting for operative treatment of tibia fracture nonunion were enrolled in a prospective data registry. Enrolled patients were followed at regular intervals for 12 months. Preoperative and 12 week postoperative radiographs were reviewed and scored using the RUST criteria. Postoperative time to union was determined by clinical and radiographic measures. Multivariate regressions were conducted to predict time to union using preoperative and postoperative RUST while controlling for treatment method. Receiver operating characteristic (ROC) curve was conducted to determine the accuracy of preoperative RUST in predicting failure of treatment.

RESULTS

Sixty-eight patients with aseptic tibia fracture nonunion treated operatively were identified. Sixty-one patients achieved union. Mean preoperative RUST was 7.5 (SD 1.4). Mean postoperative RUST was 9.2 (SD 1.4). Multivariate linear regressions demonstrated that preoperative (p = 0.043) and postoperative (p = 0.007) RUST are significant predictors of time to union after tibia fracture nonunion surgery. ROC curve demonstrated preoperative RUST below 7 was a good predictor of developing persistent tibia fracture nonunion (AUC = 0.83, Sensitivity = 1.000, Specificity = 0.745).

CONCLUSIONS

RUST preoperatively and postoperatively predicts outcome after nonunion surgery. RUST can be used as part of the complete clinical picture to shape patient expectations and guide treatment.

Extra-articular Lateral Hinge Fracture Does Not Affect the Outcomes in Medial Open-Wedge High Tibial Osteotomy Using a Locked Plate System

PURPOSE

To compare the radiologic and clinical outcomes in patients with and without lateral hinge fractures (LHFs) during medial open-wedge high tibial osteotomy (MOWHTO) using a locked plate system, as well as to assess whether LHFs could affect the midterm outcomes.

METHODS

From May 2008 to November 2015, 164 knees underwent MOWHTO using a locked plate system for the treatment of knee osteoarthritis. LHFs were recognized by radiographs during or after the high tibial osteotomy and were not additionally treated. In all patients, we applied the same rehabilitation protocol that allowed full weight bearing at 6 weeks. Patients were divided into LHF (types I and II) and nonfracture groups. Radiologically, we compared any serial changes in the hip-knee-ankle angle, femorotibial angle, medial proximal tibial angle, and posterior tibial slope angle from the immediate postoperative radiographs to the final radiographs. The union process of the osteotomy site among the groups was also evaluated. Clinically, the postoperative American Knee Society Score and knee range of motion at latest follow-up were compared. Postoperative complications were also evaluated.

RESULTS

The average age at operation was 56.0 years (range, 42-67 years), and the average follow-up period was 62.2 months (range, 24-120 months). LHFs were observed in 37 knees (22.6%) and were divided into the type I (16 knees) and type II (21 knees) groups. All groups showed no significant changes in serial evaluations of the postoperative hip-knee-ankle angle, femorotibial angle, medial proximal tibial angle, and posterior tibial slope angle. The improvements in the American Knee Society Score and knee range of motion were not significantly different among the groups. No patients showed correction loss or union problems.

CONCLUSIONS

Type I and II LHFs in MOWHTO using a medial locked plate system and relatively conservative rehabilitation protocol with full weight-bearing walking commenced at 6 weeks postoperatively showed no radiologic changes or functional deterioration during midterm follow-up.

LEVEL OF EVIDENCE

Level IV, case series.